<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #canvas {
            display: block;
            box-shadow: 0 5px 5px rgba(0, 0, 0, 0.3);
            margin: auto;
        }
    </style>
</head>

<body>
    <canvas id="canvas" width="500" height="700"></canvas>

    <script>
        var canvas = document.querySelector("#canvas");

        var ctx = canvas.getContext('2d');

        for (var i = 0; i < 5; i++) {
            ctx.beginPath()
            ctx.fillStyle = 'red'
            ctx.arc(100 + i * 60, 100, 30, 0, 2 * Math.PI)
            ctx.fill()
        }

        var red = 120;
        var green = 80;
        var blue = 120;

        for (var i = 0; i < 10; i++) {
            ctx.beginPath()
            ctx.fillStyle = 'rgb(' + (red + i * 10) + ',0,0)'
            ctx.arc(200, 300 + i * 30, 30, 0, 2 * Math.PI)
            ctx.fill()
        }
    </script>
</body>

</html>